Why Does E=mc2?

Why Does E=mc2? : (and Why Should We Care?)

3.99 (5,708 ratings by Goodreads)
By (author)  , By (author) 

Free delivery worldwide

Available. Dispatched from the UK in 3 business days
When will my order arrive?


This is an engaging and accessible explanation of Einstein's equation that explores the principles of physics through everyday life. Professor Brian Cox and Professor Jeff Forshaw go on a journey to the frontier of 21st century science to consider the real meaning behind the iconic sequence of symbols that make up Einstein's most famous equation. Breaking down the symbols themselves, they pose a series of questions: What is energy? What is mass? What has the speed of light got to do with energy and mass? In answering these questions, they take us to the site of one of the largest scientific experiments ever conducted. Lying beneath the city of Geneva, straddling the Franco-Swiss boarder, is a 27 km particle accelerator, known as the Large Hadron Collider. Using this gigantic machine - which can recreate conditions in the early Universe fractions of a second after the Big Bang - Cox and Forshaw will describe the current theory behind the origin of mass. Alongside questions of energy and mass, they will consider the third, and perhaps, most intriguing element of the equation: 'c' - or the speed of light. Why is it that the speed of light is the exchange rate?Answering this question is at the heart of the investigation as the authors demonstrate how, in order to truly understand why E=mc2, we first must understand why we must move forward in time and not backwards and how objects in our 3-dimensional world actually move in 4-dimensional space-time. In other words, how the very fabric of our world is constructed. A collaboration between two of the youngest professors in the UK, "Why Does E=MC2?" promises to be one of the most exciting and accessible explanations of the theory of relativity in recent years.show more

Product details

  • Paperback | 272 pages
  • 128 x 194 x 22mm | 399.99g
  • The Perseus Books Group
  • Da Capo Press Inc
  • Cambridge, MA, United States
  • English
  • Special edition
  • Special
  • 0306819112
  • 9780306819117
  • 3,088

About Brian Cox

Brian Cox is a professor of particle physics and Royal Society University Research Fellow at the University of Manchester. He divides his time between Manchester in the UK and the CERN laboratory in Geneva, where he heads an international project to upgrade the giant ATLAS and CMS detectors at the Large Hadron Collider. He has received many awards for his work promoting science, including being elected an International Fellow of the Explorers Club in 2002, an organisation whose members include Neil Armstrong and Chuck Yeager. He is also a popular presenter on TV and radio, with credits which including a six-part series on Einstein for BBC Radio 4, 3 BBC Horizon programs on Gravity. Time and Nuclear Fusion, and a BBC4 documentary about the LHC at CERN, "The Big Bang Machine". He was the Science Advisor on Danny Boyle's movie, the science-fiction thriller Sunshine. Brian also has an unorthodox background in the music business, having toured the world with various bands and played keyboard with D:REAM, who had several UK Top 10 hits including Things Can Only Get Better (re-released & used as Tony Blair's election anthem back in 1997. Jeff Forshaw is professor of theoretical physics at the University of Manchester, specializing in the physics of elementary particles. He was awarded the Institute of Physics Maxwell Medal in 1999 for outstanding contributions to theoretical physics. He graduated from Oxford University and gained a PhD from Manchester University. From 1992-1995 he worked in Professor Frank Close's group at the Rutherford Appleton Laboratory before returning to Manchester in 1995. Jeff is an enthusiastic lecturer and currently teaches Einstein's Theory of Relativity to first year undergraduates. He has co-writing an undergraduate textbook on relativity for Wiley and he is the author of an advanced level monograph on particle physics for Cambridge University Press.show more

Review quote

"I can think of no one, Stephen Hawking included, who more perfectly combines authority, knowledge, passion, clarity and powers of elucidation than Brian Cox. If you really want to know how Big Science works and why it matters to each of us in the smallest way then be entertained by this dazzlingly enthusiastic man. Can someone this charming really be a professor?" Stephen Fry "(The authors have)blazed a clear trail into forbidding territory, from the mathematical structure of space-time all the way to atom bombs, astrophysics and the origin of mass." The New Scientist "(This book) is clear, sparkling in places, and totally without vanity... anyone with an adventurous mind should be intrigued by what two smart physicists say about (relativity theory) in plain language...[A] delightful little book." The Huffington Post"show more

Rating details

5,708 ratings
3.99 out of 5 stars
5 33% (1,884)
4 40% (2,298)
3 21% (1,209)
2 4% (243)
1 1% (74)

Our customer reviews

This is a great book on the basic subjects of space and time in relativity, and how the revolutions in these concepts are central to current physics thought. It is told in a narrative style which is highly accessible, and enaging, to readers unfamiliar with the topic. The mathematics involved is complex, but is discussed in a very clear fashion, so even with minimal background, it's basically understandable. The book tackles some weighty issues, which certainly isn't unusual for a theoretical physics book, but one of the key features of this book is that the authors never lose sight of how important it is to confirm theory with experiment. Nor do they forget that the average reader doesn't care about esoteric concepts. They want to know why the theories are important in their lives. The physicists certainly address this concept.show more
by aira bautista
I learnt a lot reading this, and I even think I understood some of it. The first part takes you through the historical background to Einstein's famous equation, starting with Galileo's discovery that all motion is motion relative to something else (there's no absolute motion), then to the even more startling discovery that there's no absolute time, either (no 'big clock in the sky'), and the replacement of separate space and time with 'spacetime'. Spacetime must be curved (because Euclidian geometry won't work) and everything moves at speed through it (when I'm sitting down - not moving in space relative to myself - in one second I've still gone distance 'c' in spacetime). The authors make these strange concepts seem much more credible than I could ever do, and even explain why the concepts are bizarre to us (our conventional ones have been ingrained by natural selection). In the later part, the book looks at the implications of all this: how destroying mass creates a vast amount of energy (in an atom bomb, for instance), how stars burn and how E=mc2 explains other astronomical phenomena like white dwarves, neutron stars and black holes; what the scary-looking Standard Model equation means, and the world of very small elementary particles (which are, yikes, also waves), and how experiments are done nowadays at CERN and elsewhere to get them interacting. Among all this a lot of background gets pretty seamlessly filled in about how science works ('concepts must be testable by experiment'); what equations are for (allow you to predict the result of an experiment without having to conduct it); the mystery of why maths is so good at describing underlying natural phenomena; the importance of causality; and how light itself isn't special (it's just that its photons have zero mass and therefore always go at the universal maximum speed through space). For a reader like me (with long-ago O level Physics), it was fine - you have to know (or learn) that, for instance E=mc�² can become m=E/c�² but that's about it. The book also often tells you the same thing several times - but that's actually helpful, rather than annoying, in a complex subject like this. I've never read such a good popular-science book.show more
by Jonathan Pseud
Book ratings by Goodreads
Goodreads is the world's largest site for readers with over 50 million reviews. We're featuring millions of their reader ratings on our book pages to help you find your new favourite book. Close X